Self-stressed steel fiber reinforced concrete as negative moment connection for strengthening of multi-span simply-supported girder bridges

摘要

A self-stressed steel fiber reinforced concrete (SS-SFRC) moment connection is proposed to strengthen multi-span simply-supported T-section reinforced concrete (RC) girders. In the proposed moment connection technique, old concrete needs to be removed from adjacent girder ends and negative moment reinforcement is placed into cast-in-place SS-SFRC to develop continuity over the interior support. Two series of tests consisting of 15 girder specimens were conducted to investigate the reliability of the proposed SS-SFRC moment connection. An analytical model is presented to predict the load-carrying capacity of the resulting continuous composite girders. Test results show that SS-SFRC is excellent in preventing concrete cracking at the interior support. Both the load-carrying capacity and the serviceability of the strengthened girders are significantly improved. The analytical model is demonstrated to predict the load-carrying capacity of the resulting continuous composited girders with an acceptable degree of accuracy.